1. Field of the Invention
This invention relates to method and apparatus for detecting damage of refractory materials injected and used within a blast furnace to repair the furnace body from outside.
2. Description of the Prior Art
The technique of repairing a damaged part of a blast furnace wall by injecting a fluid refractory material from outside the furnace is already known from publications by the present inventors such as, for example, Japanese Laid Open Patent 123501/50, Published on Sept. 29, 1975, and U.S. Pat. No. 4,102,694.
The above mentioned repairing methods repair only the local damaged part of the blast furnace wall from outside the furnace, and are therefore different from relining the entire furnace, and can be applied to the blast furnace even during the operation thereof, and contribute greatly to extending the life of the furnace.
However, the part repaired by injecting and solidifying the fluid refractory material naturally has different characteristics than the furnace wall lined with firebricks. In some cases, the repaired part will be again damaged earlier than the other parts.
However, a technique of determining the damage of the refractory material during the use of the furnace with metallic coaxial lines or metallic parallel lines (ED-sensor) embedded in the refractory material in building the blast furnace or another furnace is also known from the Japanese Laid Open Patent No. 133207/49, Published on Dec. 20, 1974 by one of the present inventors.